Differential effects of anti-B7-1 and anti-B7-2 monoclonal antibody treatment on the development of diabetes in the nonobese diabetic mouse.

Insulin-dependent diabetes mellitus (IDDM) is thought to be an immunologically mediated disease resulting in the complete destruction of the insulin-producing islets of Langerhans. It has become increasingly clear that autoreactive T cells play a major role in the development and progression of this disease. In this study, we examined the role of the CD28/B7 costimulation pathway in the development and progression of autoimmune diabetes in the nonobese diabetic (NOD) mouse model. Female NOD mice treated at the onset of insulitis (2-4 wk of age) with CTLA4Ig immunoglobulin (Ig) (a soluble CD28 antagonist) or a monoclonal antibody (mAb) specific for B7-2 (a CD28 ligand) did not develop diabetes. However, neither of these treatments altered the disease process when administered late, at > 10 wk of age. Histological examination of islets from the various treatment groups showed that while CTLA4Ig and anti-B7-2 mAb treatment blocked the development of diabetes, these reagents had little effect on the development or severity of insulitis. Together these results suggest that blockade of costimulatory signals by CTLA4Ig or anti-B7-2 acts early in disease development, after insulitis but before the onset of frank diabetes. NOD mice were also treated with mAbs to another CD28 ligand, B7-1. In contrast to the previous results, the anti-B7-1 treatment significantly accelerated the development of disease in female mice and, most interestingly, induced diabetes in normally resistant male mice. A combination of anti-B7-1 and anti-B7-2 mAbs also resulted in an accelerated onset of diabetes, similar to that observed with anti-B7-1 mAb treatment alone, suggesting that anti-B7-1 mAb's effect was dominant. Furthermore, treatment with anti-B7-1 mAbs resulted in a more rapid and severe infiltrate. Finally, T cells isolated from the pancreas of these anti-B7-1-treated animals exhibited a more activated phenotype than T cells isolated from any of the other treatment groups. These studies demonstrate that costimulatory signals play an important role in the autoimmune process, and that different members of the B7 family have distinct regulatory functions during the development of autoimmune diabetes

A survey of chronic rhinitis in Hong Kong

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Minimization of current stress on the grid synchronization of doubly-fed induction generators for wind power generation

Author name used in this publication: S. L. HoAuthor name used in this publication: K. W. E. ChengVersion of RecordPublishe

香港977位慢性鼻炎患者的過敏原皮膚點刺測試結果

OBJECTIVES: To evaluate the prevalence of aetiological allergens identifiable by skin prick test alone in patients suffering from chronic rhinitis in Hong Kong, and also compare the clinical history and symptoms of skin prick test-positive versus skin prick test-negative patients. DESIGN: Prospective study. SETTING: Otorhinolaryngology clinic in Queen Mary Hospital of Hong Kong. PATIENTS: A total of 977 patients suffering from chronic rhinitis were recruited into the study. Skin prick test was performed with a panel of allergens including house dust mites, cockroach, cat, dog, moulds, and pollens. MAIN OUTCOME MEASURES: Skin prick test results and their correlation with symptoms. RESULTS: Of the 977 patients, 651 (67%) had positive skin prick test reactions. The commonest allergen was house dust mite which was positive in 63% of the 977 patients and 95% of those 651 skin prick test-positive patients. The other allergens were in order of cockroach (23%), cat (14%), dog (5%), pollen (4%), and mould (3%). Compared with skin prick test-negative patients, skin prick test-positive patients were more likely to have earlier age of onset of the chronic rhinitis, association with asthma, more severe symptom in the morning, more severe symptoms of itchy nose, sneezing, nasal discharge, itchy eye, and watery eye. CONCLUSIONS: Identifiable aeroallergens could be detected in 67% chronic rhinitis patients by skin prick test alone. House dust mites were the most prevalent causative allergen. There were significant differences of patterns of clinical history and symptoms severity between skin prick test-positive and skin prick test-negative patients.published_or_final_versio

Structural and Functional Brain Remodeling during Pregnancy with Diffusion Tensor MRI and Resting-State Functional MRI

Although pregnancy-induced hormonal changes have been shown to alter the brain at the neuronal level, the exact effects of pregnancy on brain at the tissue level remain unclear. In this study, diffusion tensor imaging (DTI) and resting-state functional MRI (rsfMRI) were employed to investigate and document the effects of pregnancy on the structure and function of the brain tissues. Fifteen Sprague-Dawley female rats were longitudinally studied at three days before mating (baseline) and seventeen days after mating (G17). G17 is equivalent to the early stage of the third trimester in humans. Seven age-matched nulliparous female rats served as non-pregnant controls and were scanned at the same time-points. For DTI, diffusivity was found to generally increase in the whole brain during pregnancy, indicating structural changes at microscopic levels that facilitated water molecular movement. Regionally, mean diffusivity increased more pronouncedly in the dorsal hippocampus while fractional anisotropy in the dorsal dentate gyrus increased significantly during pregnancy. For rsfMRI, bilateral functional connectivity in the hippocampus increased significantly during pregnancy. Moreover, fractional anisotropy increase in the dentate gyrus appeared to correlate with the bilateral functional connectivity increase in the hippocampus. These findings revealed tissue structural modifications in the whole brain during pregnancy, and that the hippocampus was structurally and functionally remodeled in a more marked manner.published_or_final_versio

The effect of SARS on the price of re-entrants in multi-storey apartment buildings

Natural lighting and ventilation have long been a primary consideration in building design, particularly for those high-rise and densely packed apartment blocks where mechanical ventilation is normally secondary. In Hong Kong, there are prescriptive legal requirements governing the provision of natural lighting and ventilation in private buildings. This, coupled with developers’ profit-maximizing incentives, often gives rise to re-entrant designs commonly found in apartment buildings in Hong Kong. This paper aims to study the economic impacts of the disposition of re-entrants on property prices with reference to the revelation of the chimney effect of re-entrants after the occurrence of the mass community outbreak of Severe Acute Respiratory Disease (SARS) in Amoy Gardens in 2003. In this study, we use a hedonic pricing model to examine whether flats designed with a re-entrant is sold at a different price than those without a re-entrant. We draw a sample of property transactions from a popular single residential development with variations in re-entrant designs. A total of 357 transactions were collected, of which 90 were transacted after the SARS event. The model is capable to monitor any significance changes in the premium of re-entrant and its relationship with floor level before and after SARS. Based on the hedonic pricing analysis, we found that the preference for re-entrants is floor-dependent. Before SARS, homebuyers were not fond of re-entrants on low floor levels, but they were willing to pay more for re-entrants as the floor level increases. Yet, the outbreak of SARS did not significantly change their preferences for re-entrants. The market is capable to capitalize the building design into property prices. Developers and designs should improve their building design to meet the ever changing needs of the market. This paper provides an empirical framework to examine how homebuyers price a particular design feature using property transaction data.published_or_final_versio

An empirical study on the neighbourhood effect of refurbishment

An important portion of property value comes from property location, which is a function of the quality of surrounding environment (e.g. external views). In a congested living environment like Hong Kong, it is difficult, if not impossible, to have a view unobstructed by buildings. As such, the quality of views is dependent upon the aesthetic quality of surrounding buildings. It is likely that poorly maintained buildings will emit negative visual effects to their immediate neighbourhood. Refurbishing these poor buildings should, therefore, reduce or even counter this negative externality. This study aims to empirically identify the effect of refurbishment on the prices of neighbourhood properties based on an analysis of panel data in Hong Kong. The data consists of property transactions in a large housing estate located in Pokfulam. This estate was chosen because its surrounding buildings underwent refurbishment in 1998. Results show that the refurbishment brought a significant increase in the price of properties facing the refurbished buildings, keeping other things constant. Given the aging building problem in most urban areas, the results pose significant practical implications on building refurbishment and urban rehabilitation as a whole. Developers or property owners may be lured to invest in the refurbishment of adjacent dilapidated properties with a view to a value enhancement of their own properties.published_or_final_versio

Initial results of selective renal parenchymal clamping with an adjustable kidney clamp in nephron-sparing surgery: an easy way to minimise renal ischaemia

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Effects of risk assessment and management programme for hypertension on clinical outcomes and cardiovascular disease risks after 12 months: a population-based matched cohort study

Objectives: This study evaluated the effectiveness of a structured multidisciplinary risk assessment and management programme for patients with hypertension (RAMP-HT) who were managed in public primary care clinics but had suboptimal blood pressure (BP) control in improving BP, LDL-cholesterol (LDL-C) and predicted 10-year cardiovascular disease (CVD) risk after 12 months of intervention. Methods: A total of 10 262 hypertension patients with suboptimal BP despite treatment, aged less than 80 years and without existing CVD were enrolled in RAMP-HT between October 2011 and March 2012 from public general out-patient clinics in Hong Kong. Their clinical outcomes and predicted 10-year CVD risk were compared with a matched cohort of hypertension patients who were receiving usual care in general out-patient clinics without any RAMP-HT intervention by propensity score matching. Multivariable linear and logistic regressions were used to determine the independent effectiveness of RAMP-HT after adjusting for potential confounding variables. Results: Compared with the usual care group after 12 months, significantly greater proportions of RAMP-HT participants achieved target BP (i.e. BP 20%) (OR = 1.13, P < 0.01). RAMP-HT participants also had significantly greater reduction in predicted 10-year CVD risk by 0.44% (coefficient = -0.44, P < 0.01). Conclusion: The structured multidisciplinary RAMP-HT was more effective than usual care in achieving target BP, LDL-C and reducing predicted 10-year CVD risk in public primary care patients with suboptimal hypertension control after 12 months of intervention. A long-term follow-up should be conducted to confirm whether the improvement in clinical outcomes can be translated into actual reductions in CVD complications and mortalities and whether such approach is cost-effective.published_or_final_versio

Heterogeneity of passenger exposure to air pollutants in public transport microenvironments

Epidemiologic studies have linked human exposure to pollutants with adverse health effects. Passenger exposure in public transport systems contributes an important fraction of daily burden of air pollutants. While there is extensive literature reporting the concentrations of pollutants in public transport systems in different cities, there are few studies systematically addressing the heterogeneity of passenger exposure in different transit microenvironments, in cabins of different transit vehicles and in areas with different characteristics. The present study investigated PM2.5 (particulate matter with aerodynamic diameters smaller than 2.5μm), black carbon (BC), ultrafine particles (UFP) and carbon monoxide (CO) pollutant concentrations in various public road transport systems in highly urbanized city of Hong Kong. Using a trolley case housing numerous portable air monitors, we conducted a total of 119 trips during the campaign. Transit microenvironments, classified as 1). busy and secondary roadside bus stops; 2). open and enclosed termini; 3). above- and under-ground Motor Rail Transport (MTR) platforms, were investigated and compared to identify the factors that may affect passenger exposures. The pollutants inside bus and MTR cabins were also investigated together with a comparison of time integrated exposure between the transit modes. Busy roadside and enclosed termini demonstrated the highest average particle concentrations while the lowest was found on the MTR platforms. Traffic-related pollutants BC, UFP and CO showed larger variations than PM2.5 across different microenvironments and areas confirming their heterogeneity in urban environments. In-cabin pollutant concentrations showed distinct patterns with BC and UFP high in diesel bus cabins and CO high in LPG bus cabins, suggesting possible self-pollution issues and/or penetration of on-road pollutants inside cabins during bus transit. The total passenger exposure along selected routes, showed bus trips had the potential for higher integrated passenger exposure compared to MTR trips. The present study may provide useful information to better characterize the distribution of passenger exposure pattern in health assessment studies and the results also highlight the need to formulate exposure reduction based air policies in large cities. © 2015 Elsevier Ltd.postprin